1,7,13-Trimethyl-4,10,16-tris(1-methylethyl)-6H,12H,18H-tribenzo[b,f, j][1,5,9 ]trioxacyclododecin-6,12,18-trione-3-buten-2-ol (2/1), C₃₃H₃₆0₆.½C₄H₈O, Mr = 564.70, trigonal, P3₁21, a = 13.444(3), c = 30.217(9)Å, V = 4730(1)ų, Z = 6, Dx = 1.190 g cm⁻³, λ(Mo Kα) = 0.71069 Å, μ = 0.875 cm⁻¹, F(000) = 1812, T = 153 K, R = 0.068 for 1657 observed reflections at the |Fo| > 3σ(Fo) level. The host structure was refined starting from previously determined coordinates in an isomorphous tri-o-thymotide (TOT) clathrate. A strained conformation of the guest, derived from a calculated two-dimensional energy map, was favourably used as rigid component in the X-ray model. Evidence for low chiral discrimination of the guest was quantitatively demonstrated. Correlation of configuration between TOT in a single crystal and the major included enantiomer was shown to obey previously established structural rules. Lattice- energy calculations corroborate the experimental observations.